Hoatzin

It is the only member of its family (Opisthocomidae), though some taxonomists also place them in their own order. They retain some characteristics that are not found in any other birds. For instance, as chicks they still retain claws on the ends of their wings, which aid them in climbing and clinging to trees.

Regardless of how they fit into the evolutionary picture, they are stunning ancient animals.

Hoatzin

It is the only member of its family (Opisthocomidae), though some taxonomists also place them in their own order. They retain some characteristics that are not found in any other birds. For instance, as chicks they still retain claws on the ends of their wings, which aid them in climbing and clinging to trees.

Regardless of how they fit into the evolutionary picture, they are stunning ancient animals.